PARIS – French President Nicolas Sarkozy on Sunday fiercely rejected reports that he was offered campaign funding from late Libyan leader Moammar Gadhafi, as new challenges piled up for Sarkozy a week before France’s presidential runoff.

Sarkozy also rebuffed leftist critics who compared his campaign rhetoric to that of France’s Nazi collaborators, as ugly wartime memories surfaced in what has been a particularly bitter presidential race.

Polls predict Sarkozy will lose the May 6 runoff to Socialist Francois Hollande, who promises government-funded jobs programs and higher taxes on the rich – pledges that resonate with a recession-weary electorate.

The campaign-funding allegation originates from a year-old claim by Gadhafi’s second son, Seif al-Islam Gadhafi, that Libya financed Sarkozy’s 2007 presidential bid. The allegation came as Sarkozy was campaigning for international airstrikes against Gadhafi’s forces to stop his crackdown on Libyan rebels.

Although no evidence has emerged that the funding ever took place, French website Mediapart reported Saturday that it had obtained a 2006 Libyan document signed by Gadhafi’s then-intelligence chief Moussa Koussa with an offer by the regime to spend C50 million on Sarkozy’s campaign.

“It’s a setup, it’s a slanderous remark,” Sarkozy said on Canal Plus television Sunday, accusing Mediapart of being a mouthpiece “of the left.”

Hollande’s campaign team has urged judicial authorities to investigate, as has Segolene Royal, the runner-up in the 2007 race.

Supporters of the Socialist leader gathered Sunday for a rally in the French capital Paris, that some were already comparing to a victory party.

It’s “a beautiful moment of the end of the campaign,” said Guillaume Gouffier-Cha, a member of the Young Socialists Movement. “The expectations are enormous … It feels good.”

Earlier in the day, Hollande honoured Jews deported during World War II, visiting a memorial and museum to the Holocaust in Paris and praising the museum’s work as crucial “for Jews and for humanity.”

Some 76,000 Jews were deported from Nazi-occupied France to concentration camps, and the overwhelming majority never returned.

Sarkozy has come under criticism during the presidential campaign for his tough language toward immigrants – language that far-left party candidate Jean-Luc Melenchon and environmental candidate Eva Joly have compared to that of France’s Nazi collaborators.

Sarkozy called the comparisons “so insulting and excessive that they demean those who pronounce them,” in an interview with the daily Le Parisien published Sunday.

He has stepped up his rhetoric since anti-immigrant far right leader Marine Le Pen scored a strong third-place showing in the first round of the presidential election April 22.

Le Pen’s voters could be crucial to deciding who wins the runoff. Her father and the founder of her National Front party, Jean-Marie Le Pen, has been convicted of racism and anti-Semitism. Marine Le Pen has focused her ire on what she calls the “Islamization” of France.

Sarkozy has also dismissed suggestions that his conservative party UMP helped discredit former International Monetary Fund chief Dominique Strauss-Kahn.

Strauss-Kahn was considered the leading presidential hopeful a year ago but was then arrested and charged with assaulting a New York hotel maid. The charges were later dropped. A report in the Guardian newspaper says Strauss-Kahn believes his political opponents sabotaged him.